SU1707201A1 - Method of bench working by blasting - Google Patents

Abstract

The invention relates to mining and m. used in the formation of the surface of the non-working pit side of the quarry mainly in permafrost conditions. The purpose of the invention is to increase the integrity of the edge array of rocks by reducing the zone of weakening and cracking in it by concentrating the explosion energy of the e-plane of the exposed surface. In the rocks of the ledge there is a drill of a row of fender, contour and additional rows of wells. An additional row of wells is drilled along the proposed boundary of the zone of rock formation. The wells are charged with dispersed charges. The wells in additional wells are arranged in a staggered order relative to the adjacent wells of this row. Produces short-term slow blasting of firing and contour wells. Additional wells explode after blasting contour wells. Moreover, these wells in the row are blown up with the slowing down of each subsequent well, defined by the expression given in the description. 3 il.

Description

The invention relates to mining and can be used in the formation of the surface of the benches of the non-working pit wall, mainly in permafrost conditions.

The purpose of the invention is to increase the integrity of the edge array of rocks by reducing the zone of weakening of crack formation therein by concentrating the explosion energy in the plane of the reflected surface.

FIG. Figure 1 shows the layout of wells in a transverse section of the ledges; in fig. 2 — double circuit blasting wells with cumulative charges; in fig. 3 - contour wells. cross section.

The method is carried out as follows. On the ledges of the quarry, first of all, the fenders and the traditional row of wells 1 of the screening (cut) slot in the plane of the limiting contour are first drilled, then at a distance of 0.5–1, Om is drilled and the row of wells contour blasting 2, located 0.8–1.5 m along the supposed border of the out-of-tubing zone of weakened, fractured rocks 3, along with the main blast holes 4. In addition, the additional wells 2 are charged with cumulative distributed (rus) charges 5 with double cumulative notch 6, staggered relative to adjacent wells, with

the direction of accumulation in the plane of these additional (contour) wells 2 and explode in the last turn 30-50 ms after the explosion of wells 4, and each adjacent well with a staggered arrangement of cumulative charges blows up at different times with deceleration,

where i

SLE.

from my expression

Uses.

well spacing, m; Usace - speed of a blast wave, m / s.

In order to further reduce the effect of the explosion on the solidity of the contoured array, it is preferable to use a low blasting explosive, for example, propellant explosives, moisture-proof smokeless powder.

In the contour plane of the wells drilled along the boundary of the zone of weakened rocks corresponding to the marginal contour of the quarry, provide a high concentration of explosion energy to form a smooth cutting surface of the slope. Cumulative blasting in a given direction provides a concentration of explosion energy of 10-20 times, which in this case is carried out in two directions in the same plane.

In addition, when a cut-off slot is formed, the position of the energy of the direct explosion wave to the energy of the reverse wave is carried out. For this, an additional row of wells is blown up in two stages with the time difference necessary for the passage of the blast wave from one well, for example, odd, to another, for example, even, i.e.

Dg

SLE.

Vcrtte.

where ICKB is the distance between wells, m;

Vcefle. - velocity of the blast wave in the massif, m / s, which depends on the physicomechanical properties of rocks.

As a result, the explosion energy concentrates on the formation of a gap through additional wells, exceeding 30-50 times

compared with the traditional explosion, respectively, the charge weight and the lateral impact of the explosion are reduced, aimed at maintaining the integrity of the contour

rock mass quarry.

An insignificant layer of weakened rocks on the wall of the escarpment formed by contour blasting is cleaned using a roller roller, exposing the monolithic

array The surface of the monolithic mass of the slope is insulated by coating with fiberglass, excluding the alternating thermal conditions in the mountain of the slope. If there is a weakened area on the slope, it is pre-fastened, for example, by forcing cement mortar into the massif.

Ultimately, a slope in a more monolithic landscape is achieved. ,

Claims (1)

Formula of the Invention A method of explosive development of ledges, including drilling of a series of firing and contour wells, charging them with dispersed charges, short-delayed blasting of wells, in order to improve the integrity of the boundary rock mass by reducing the zone of weakening and fracturing - developing therein by concentrating the energy of the explosion in the plane of the exposed surface, we drill an additional row of wells along the supposed boundary of the zone of weakening of the rocks, charging them with cumulative charges, torye a downhole staggered with respect to adjacent wells and blasting said series of wells is produced out after blasting contour wells with deceleration of each subsequent well in the row, defined by the expression of five 0 five 0 five ten , -3 I  SLE. Vceftc. where is 1 well spacing, m; Vceflc. - speed of a blast wave, m / s. g i one Phie.1 Aa - 22 56 fie.Z